Electrically isolated support for overlying MEM structure

Abstract

MEM devices are fabricated with integral dust covers, cover support posts and particle filters for reduced problems relating to particle contamination. In one embodiment, a MEM device ( 10 ) includes an electrostatic actuator ( 12 ) that drives a movable frame ( 14 ), a displacement multiplier ( 16 ) for multiplying or amplifying the displacement of the movable frame ( 14 ), and a displacement output element ( 18 ) for outputting the amplified displacement. The actuator ( 12 ) is substantially encased within a housing formed by a cover ( 36 ) and related support components disposed between the cover ( 36 ) and the substrate ( 38 ). Electrically isolated support posts may be provided in connection with actuator electrodes to prevent contact between the cover and the underlying electrodes. Such a support post may also incorporate an electric filter element for filtering undesired components from a drive signal. Particle filters may be provided in connection with etch release holes or other openings in order to further protect against particle contamination.

What is claimed:  
     
         1 . A MEM apparatus comprising: 
 a substrate;    a first structure supported on said substrate;    an electrostatic component disposed between said substrate and said first structure and extending across an area of said substrate; and    at least one support structure disposed within said area of said substrate for supporting said first structure.    
     
     
         2 . A MEM apparatus as set forth in  claim 1 , wherein said electrostatic component comprises a movable electrode.  
     
     
         3 . A MEM apparatus as set forth in  claim 1 , wherein said electrostatic component comprises a static electrode.  
     
     
         4 . A MEM apparatus as set forth in  claim 1 , wherein said electrostatic component includes a movable electrode and a static electrode.  
     
     
         5 . A MEM apparatus as set forth in  claim 4 , wherein said support structure is positioned proximate to said static electrode.  
     
     
         6 . A MEM apparatus as set forth in  claim 1 , wherein said support structure has a height, relative to an axis extending between said first structure and said substrate, greater than a height of said electrostatic component, wherein said support structure maintains a separation between said first structure and said electrostatic component.  
     
     
         7 . A MEM apparatus as set forth in  claim 1 , wherein said at least one support structure comprises multiple support structures distributed across an area of said first structure.  
     
     
         8 . A MEM apparatus as set forth in  claim 1 , wherein said support structure is substantially electrically isolated from said electrostatic component.  
     
     
         9 . An MEM apparatus as set forth in  claim 1 , wherein said electrostatic element comprises a movable element that is movable across a range of positions and said support structure is positioned to avoid mechanical interference with said movable element as said movable element moves across said range of positions.  
     
     
         10 . A MEM apparatus comprising: 
 a substrate;    a first structure supported on said substrate;    a movable component disposed between said substrate and said first structure and extending across an area of said substrate; and    at least one support structure disposed within said area of said substrate for supporting said first structure.    
     
     
         11 . A MEM apparatus as set forth in  claim 10 , wherein said movable component includes a movable electrode and a static electrode and said support structure is positioned proximate to said static electrode.  
     
     
         12 . A MEM apparatus as set forth in  claim 10 , wherein said support structure has a height, relative to an axis extending between said first structure and said substrate, greater than a height of said movable component, wherein said support structure maintains a separation between said first structure and said movable component.  
     
     
         13 . A MEM apparatus as set forth in  claim 10 , wherein said at least one support structure comprises multiple support structures distributed across an area of said first structure.  
     
     
         14 . A MEM apparatus as set forth in  claim 10 , wherein said support structure is substantially electrically isolated from said movable component.  
     
     
         15 . An MEM apparatus as set forth in  claim 10 , wherein said movable component is movable across a range of positions and said support structure is positioned to avoid mechanical interference with said movable component as said movable component moves across said range of positions.  
     
     
         16 . A MEM apparatus, comprising: 
 a movable optical component;    an actuator mechanism for effecting movement of said optical component;    a cover extending over at least a portion of said actuator mechanism, said cover further extending across an area; and    at least one support structure, disposed within said area, for supporting said cover.    
     
     
         17 . A MEM apparatus as set forth in  claim 16  wherein said actuator mechanism comprises a movable electrode and a static electrode and said support structure is positioned proximate to said static electrode.  
     
     
         18 . A MEM apparatus as set forth in  claim 16 , wherein said support structure has a height, relative to an axis extending between said cover and a bottom surface of said actuator mechanism, greater than a height of said actuator mechanism, wherein said support structure maintains a separation between said cover and said actuator mechanism.  
     
     
         19 . A MEM apparatus as set forth in  claim 16 , wherein said at least one support structure comprises multiple support structures distributed across an area of said cover.  
     
     
         20 . A MEM apparatus as set forth in  claim 16 , wherein said support structure is substantially electrically isolated from said actuator mechanism.  
     
     
         21 . An MEM apparatus as set forth in  claim 16 , wherein said actuator mechanism comprises a movable component that is movable across a range of positions and said support structure is positioned to avoid mechanical interference with said movable component as said movable component moves across said range of positions.  
     
     
         22 . A MEM apparatus, comprising: 
 a substrate; and    a micromachined structure formed on said substrate including: 
 an electrical lead supported on said substrate; and  
 filter structure, supported on said substrate, for filtering an undesired electrical component from said lead.  
   
     
     
         23 . An apparatus as set forth in  claim 22 , wherein said filter comprises structure for establishing a capacitance between said structure and said electrical lead.  
     
     
         24 . A method for use in constructing a MEM device, comprising the steps of: 
 first establishing an active component on a substrate, said active component comprising one of movable component and an electrostatic component, said active component extending across an area of said substrate;    second establishing an overlying structure extending over at least a portion of said active component; and    third establishing at least one support structure within said area for supporting said overlying structure.    
     
     
         25 . A method as set forth in  claim 24 , wherein said active component comprises a movable electrode and a static electrode and said step of third establishing comprises positioning said support structure proximate to said static electrode.  
     
     
         26 . A MEM apparatus as set forth in  claim 24 , wherein said step of third establishing comprises forming said support structure such that said support structure has a height, relative to an axis extending between said overlying structure and said substrate, greater than a height of said active component, wherein said support structure maintains a separation between said overlying structure and said active component.  
     
     
         27 . A method as set forth in  claim 24 , wherein said step of third establishing comprises forming multiple support structures distributed across an area of said overlying structure.  
     
     
         28 . A method as set forth in  claim 24 , wherein said step of third establishing comprises substantially electrically isolating said support structure from said active component.  
     
     
         29 . A method as set forth in  claim 24 , wherein said active component comprises a movable component that is movable across a range of positions and said step of third establishing comprises positioning said support structure to avoid mechanical interference with said movable component as said movable component moves across said range of positions.